package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {


    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //1、查询优惠卷
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2、判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            //尚未开始
            return Result.fail("秒杀尚未开始！");
        }
        //3、判断秒杀是否已经结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已经结束！");
        }
        //4、判断库存是否充足
        if(voucher.getStock() < 1){
            return Result.fail("库存不足！");
        }


        Long userId = UserHolder.getUser().getId();
        //创建锁对象
        //SimpleRedisLock lock = new SimpleRedisLock("order" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("lock:order" + userId);

        //获取锁
        boolean isLock = lock.tryLock();
        //判断是否获取锁成功
        if (!isLock) {
            return Result.fail("一个用户只能下一单");
        }
        try {
            //获取代理对象（事务），解决在createVoucherOrder（）方法中加锁存在的事务没提交就释放锁的问题
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }finally {
            lock.unlock();;
        }

    }

    @Transactional
    public  Result createVoucherOrder(Long voucherId) {
        //5、一人一单
        Long userId = UserHolder.getUser().getId();
        //5.1 查询订单
        int count = query().eq("user_id",userId).eq("voucher_id", voucherId).count();
        //5.2 判断订单是否存在
        if(count > 0){
            //用户已经购买过了
            return Result.fail("用户已经购买过一次！");
        }

        //6、扣减库存
        boolean success =  seckillVoucherService.update()
                .setSql("stock = stock - 1")    //set stock = stock -1
                .eq("voucher_id", voucherId) //when Voucher_id = ? and stock > 0
                .gt("stock",0)
                .update();
        if (!success){
            return Result.fail("库存不足！");

        }
        //7、创建订单
        long voucherOrderID = redisIdWorker.nextId("order");
        VoucherOrder voucherOrder = new VoucherOrder();

        voucherOrder.setId(voucherOrderID);
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        //7、放回订单id
        return Result.ok(voucherOrderID);
    }
}
